Identification of factors that keep individuals with Alzheimer's disease (AD) from functioning optimally in their daily lives is of singular importance. Many aspects of vision and visual cognition are impaired in AD, including the abilities to recognize and discriminate objects. These impairments arise from pathological changes in high-order association areas of the brain, but also from defective input from lower-level visual processing areas. Because many healthy elderly adults and people with AD take multiple pills on a daily basis, and occasionally drop pills onto a tabletop or floor surface, a real-world search task is proposed that investigates how perceptual factors such as contrast sensitivity and depth perception affect the ability to detect a target object. Information will be acquired on acuity, contrast sensitivity and depth perception. By enhancing contrast, it is hypothesized that the ability of those with AD to conduct visual search under naturalistic conditions will be improved. This information can be used to develop effective intervention strategies aimed at sustaining independent activities of daily living and improving the quality of life of the elderly and individuals with AD. [unreadable] [unreadable] [unreadable]